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Overview

SumIt is a browser-based maths, physics and chemistry equation studio. It works fully offline as a Progressive Web App — every library and AI model is bundled locally, all data stays in your browser, no account required.

Editor

The editor uses a rich math field — you can type LaTeX directly or use the on-screen keyboard. The field itself shows the equation typeset live as you edit. Below, a single output card has tabs for the other useful representations: LaTeX, MathML, Spoken. Click any tab to switch view; the content updates live as you type.

Editor view with the equation x² + 2x + 1 = 0 and a toolbar of buttons.
Editor with toolbar and tabbed output card.

Autocomplete

As you type a word (≥ 2 letters) the autocomplete dropdown shows matching Greek letters, operators, and formula triggers. Examples:

Use / to navigate, Enter or Tab to accept, Esc to dismiss. Frequently-used suggestions float to the top of the list automatically.

Autocomplete dropdown showing 'sqrt' matching a square-root symbol.
Each suggestion is rendered typographically so you see what you'll get.

Buttons

ButtonAction
▶ Read aloudSpeaks the equation in plain English (handles \ce{} chemistry and align environments)
⊞ Multi-lineWraps the equation in an align environment — use ↵ New line or Shift+Enter to add aligned rows
⚛ PhysicsToggles the physics symbol palette and adds physics formulas to the library/autocomplete
📚 FormulasOpens the searchable formula library (300+ formulas, scoped by Physics toggle)
Copy ▾Opens a menu with: Copy LaTeX (raw source), Copy MathML (XML), Copy for Word (wrapped <math> document — paste into Word for a live equation)
Export PNGDownloads the equation as a PNG image
SaveAdds the current equation to History
ClearClears the editor

Formula Library

The library bundles 300+ named formulas across maths, physics, chemistry, engineering, and physical constants. Click 📚 Formulas in the relevant tab to open it.

The visible set is also filtered by the Level setting: ≤ 16, 16 – 18, University, or All. Picking a level shows everything up to and including it.

Use the search box to filter by name, id, or keyword. Click any card to insert the formula at the cursor; close with Esc or the ✕ button. The same trigger ids power the autocomplete dropdown.

Formula library modal with a sidebar of categories and a grid of rendered formulas.
Formula library — categorised sidebar, searchable, click-to-insert.

Speak

Click Start listening and speak your equation naturally. Examples:

The recognised text is converted to LaTeX automatically. Click Send to Editor to transfer it. Requires a browser with Web Speech API support (Chrome or Edge recommended).

Draw

Handwrite an equation on the canvas, then click Recognise. A bundled neural network (~117 MB) is loaded into memory the first time you click Recognise — subsequent recognitions are immediate. Nothing is sent to any server. If the model fails to load, recognition silently falls back to the bundled template-matcher.

Draw tab with canvas and the Train your handwriting picker expanded.
Draw tab with Live preview and the Train picker expanded.

Controls

ControlAction
Stroke sliderAdjusts pen thickness
Colour pickerChanges ink colour
Live previewRuns the fast template-matcher after every stroke and shows the rolling result. Tick to enable; default state set in Settings.
UndoRemoves the last stroke
ClearClears the canvas
RecogniseLoads the AI model on first use, then runs recognition. Long equations show a "may be cut off" warning if the decoder reaches its limit
Save PNGDownloads the canvas as an image
Send to EditorTransfers recognised LaTeX to the Editor (confirms before overwriting existing work)

Live preview & correction

With Live preview on, recognition runs after each stroke. Each detected symbol appears with a faint dashed box on the canvas — click any box to pick a different interpretation from the alternates. Picking an alternate also teaches the matcher: that drawing is silently saved as a template tagged with your chosen symbol, so future similar shapes prefer it.

To keep things stable as you write, when you start a new mark clearly to the right of everything before it, the prior strokes are committed and stop being re-evaluated — only the latest active group is recognised on each stroke.

Recognition result

The result card (visible in the Draw screenshot above) shows the rendered equation as the primary content. Use Send to Editor or Clear & retry, or click ▼ Show LaTeX to reveal the raw source. When more than one interpretation is available, Alternatives chips appear below — click any to swap the result.

Train your handwriting

Open the Train your handwriting panel to teach the template-matcher new symbols.

  1. Draw a single symbol on the canvas above.
  2. Click what you wrote. The picker shows Best guesses from the matcher plus a categorised grid of common symbols (Numbers, Operators, Brackets, Letters, Capitals, Greek, Math symbols).
  3. The drawing is saved as a user template; the canvas clears so you can train the next symbol.

Power users can still type LaTeX directly via the Advanced — type LaTeX directly details. Saved templates appear in Your saved templates; right-click (or long-press on touch) any tile to delete it. Remove my templates wipes them all.

Scientific Calculator

A full scientific calculator powered by math.js. Switch between degree and radian modes using the DEG / RAD toggle.

Scientific calculator with a 4-column keypad and memory controls.
Scientific calculator with standard 4-column layout.

Functions

Keyboard shortcuts

While the Scientific tab is active, you can type numbers and operators directly. Enter evaluates, Backspace deletes, Esc clears.

Use Send to Editor to transfer the result to the equation editor.

Graphing Calculator

Plot up to 6 functions simultaneously. Each function is colour-coded. Three modes:

Graphing calculator showing a sine wave with mode and range controls.
Graphing calculator in Cartesian mode.

Switching modes preserves your edited functions; defaults are only seeded when you haven't customised anything.

Controls

Chemistry

The Chemistry tab renders chemical formulas and reactions using the mhchem KaTeX extension. The input box accepts two flavours:

Chemistry tab rendering H2SO4 + 2NaOH -> Na2SO4 + 2H2O.
Chemistry tab with a rendered reaction.

mhchem syntax

You typeMeaning
H2OSubscript numbers (H₂O)
Ca^2+Charge superscript (Ca²⁺)
^{14}CIsotope mass number (¹⁴C)
->Reaction arrow (→)
<=>Equilibrium arrow (⇌)
v / ^Precipitate ↓ / gas ↑

Click 📚 Formulas to browse 20+ chemistry formulas, or use the chip bar for arrows, states, and special symbols.

History

Every equation you save in the Editor or Chemistry tab appears here (capped at 500 entries; older saves are auto-trimmed if storage runs short). Click Load to restore an equation to the Editor (confirms before overwriting). Click Export all (JSON) to download your full history. Stored in your browser's localStorage — never transmitted.

Accessibility

SumIt is built for keyboard, screen-reader, and reduced-motion users. Every command is reachable without a mouse.

Keyboard navigation

Global shortcuts

ShortcutAction
?Open this help in a new tab (only when not typing)
Cmd / Ctrl + KToggle the menu drawer
Cmd / Ctrl + SSave the current equation (Editor only)

Screen-reader support

Visual accommodations

Credits & Licences

SumIt is built on open-source libraries, all with licences compatible with commercial use. Full attributions and licence text live in LICENSES.md.

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